I agree with W.W., that deer was hit somewhere, that somewhere had to have been low and back of midsection. In all hopes, a graze, but there is no telling of that. If it was a gut hit, it would be pretty hard to detect in that overgrown food plot, and your search of a 10 acre field and I don't know how far of the tree line, would not be hardly enough of a search for a gut shot deer. He could go miles, especially if some coyotes got after him. Sorry to say, it just dosen't look good. Either way that buck will probably not be back. Do you know the surrounding land owners? You could put the word out to see if anyone does find it, they could at least let you know. Sometimes driving around the area and seeing buzzards and crows low in trees and close to the ground is a good indication of a dead deer. I know you feel bad about the situation, but you shouldn't, "things" happen, they have happened to us all, and as hard as we try, could easily happen again. A young hunter in all the excitment, could easily be off in the shot ( though not to blame, we all had some kind of mishape when starting out), it is a learning experience. One more reason to emphasize the importance of accuracy.
Three years ago had the same thing happen. Nice 10, early season bowshot and mule kick, no arrow, 2 drops of blood, looked for 2 days. Found him in Jan. while shed hunting. Knew it was the same deer, my arrow was there with the bones.
Look at it on the bright side, a grazed hit, which it could be just that. Time for him to get back out there.
never say never
patience is the companion of wisdom